More generic Elements and ElementsBuilder

luiz · Mar 4, 2011 · 2af6204 · 2af6204
1 parent e8d0306
commit 2af6204
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Showing 4 changed files with 21 additions and 9 deletions.
diff --git a/example/WebContent/WEB-INF/lib/vraptor-html-dsl-1.0.jar b/example/WebContent/WEB-INF/lib/vraptor-html-dsl-1.0.jar
diff --git a/src/main/java/br/com/caelum/vraptor/html/tags/builders/Elements.java b/src/main/java/br/com/caelum/vraptor/html/tags/builders/Elements.java
@@ -39,11 +39,11 @@ public void append(NestedElement child) {
 	 * @param <T>
 	 *            Type of the objects to be transformed into HTML elements
 	 * @param objects
-	 *            List of objects to be transformed into HTML elements
+	 *            Iterable of objects to be transformed into HTML elements
 	 * @return A fresh new instance of a {@link ElementsBuilder} for the given
 	 *         object list
 	 */
-	public static <T> ElementsBuilder<T> format(List<T> objects) {
+	public static <T> ElementsBuilder<T> format(Iterable<T> objects) {
 		return new ElementsBuilder<T>(objects);
 	}
 

diff --git a/src/main/java/br/com/caelum/vraptor/html/tags/builders/ElementsBuilder.java b/src/main/java/br/com/caelum/vraptor/html/tags/builders/ElementsBuilder.java
@@ -3,7 +3,7 @@
 import static com.google.common.base.Preconditions.checkArgument;
 
 import java.lang.reflect.Method;
-import java.util.List;
+import java.util.Iterator;
 
 import net.vidageek.mirror.dsl.Mirror;
 import br.com.caelum.vraptor.html.tags.interfaces.NestedElement;
@@ -60,17 +60,21 @@ private void verifyPassedMethod(Method formatter) {
 			checkArgument(formatter.getParameterTypes().length == 1,
 					"The formatting method %s must receive only one argument",
 					formatter.toGenericString());
-			checkArgument(
-					formatter.getParameterTypes()[0].equals(objects.get(0).getClass()),
-					"The formatting method %s must receive one argument of type %s",
-					formatter.toGenericString(), objects.get(0).getClass().getName());
+			Iterator<T> iterator = objects.iterator();
+			if (iterator.hasNext()) {
+				Class<? extends Object> desiredParameterClass = iterator.next().getClass();
+				checkArgument(
+						formatter.getParameterTypes()[0].equals(desiredParameterClass),
+						"The formatting method %s must receive one argument of type %s",
+						formatter.toGenericString(), desiredParameterClass.getName());
+			}
 		}
 	}
 
-	private final List<T> objects;
+	private final Iterable<T> objects;
 	private final Elements elements;
 
-	public ElementsBuilder(List<T> objects) {
+	public ElementsBuilder(Iterable<T> objects) {
 		this.objects = objects;
 		this.elements = new Elements();
 	}

diff --git a/src/test/java/br/com/caelum/vraptor/html/tags/ElementsBuilderTest.java b/src/test/java/br/com/caelum/vraptor/html/tags/ElementsBuilderTest.java
@@ -4,6 +4,7 @@
 import static org.junit.Assert.assertEquals;
 
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 
 import org.junit.Test;
@@ -52,6 +53,13 @@ public void throwsExceptionWhenTryingToUseAMethodThatReturnsASubclassOfNestedEle
 		ElementsBuilder<Integer> builder = new ElementsBuilder<Integer>(objects);
 		builder.using(new Formatter()).formatIntAndReturnTag(null);
 	}
+
+	@Test
+	public void doesNotCrashWhenFormattingAnEmptyList() throws Exception {
+		List<Integer> objects = Collections.emptyList();
+		ElementsBuilder<Integer> builder = new ElementsBuilder<Integer>(objects);
+		builder.using(new Formatter()).formatInt(null);
+	}
 }
 
 class Formatter {